However, some box-office prognosticators are now predicting a huge first-weekend gross of over $70 million.

Tracking is all over the map for this one. The full Friday box-office total will give a clearer picture, of course.

Meanwhile, Disney's "Sorcerer's Apprentice" grossed $3.2 million Friday, putting the $150 million Jerry Bruckheimer-produced fantasy film on a pace to finish its first five days under a moribund pre-release forecast of around $25 million.

It opened Wednesday to $3.9 million.

Previously:

If you're looking for an adult-targeted, two-hour, 28-minute movie with awards ambitions debuting in the heart of the summer popcorn season, you can't do much better than Warner’s “Inception.”

Rolling in Friday at 3,792 theaters in the U.S. and Canada — many of which will be offering midnight shows — the PG-13-rated sci-fi thriller packs the heavyweight talent punch of star Leonardo DiCaprio and emerging-star director, "The Dark Knight's" Christopher Nolan.

Tracking suggests the film, co-produced by Warner Bros. and Legendary Pictures at a cost of $160 million, could surpass $60 million in its first weekend.

“It has to do 50-plus, and don’t be surprised if it goes higher,” said one rival-studio distribution official.

Warner officials, of course, are more conservative, predicting a start in the $35 million-$45 million range.

"It's an original movie that's getting fabulous reviews," Warner distribution president Dan Fellman told TheWrap. "I'm sure we'll do well even if we don't open up to ann enormous number."

Given "Inception's" solid reviews (an 85 percent fresh score on Rotten Tomatoes) and overall movie-industry heat, its backers are understandably confident. Indeed, Warner’s pre-release screenings of the movie have buzz events around Hollywood for the past two weeks.

Yet, given the long runtime and Nolan’s dense dreamscape plot — DiCaprio plays a corporate espionage agent who does his thing in REM state — the film's backers are playing it on the bearish side in terms of the three-day premeire.

“It’s accessible, but not that accessible,” said another executive close to the film, who pegged the opening in the $45 million-$60 million range.

Family films are thick at the multiplex right now. Disney’s Jerry Bruckheimer-produced “Sorcerer’s Apprentice” – which reteams the “National Treasure” team of actor Nicolas Cage and director Jon Turteltaub – debuted to an estimated $3.9 million, joining a PG-rated realm that also includes Universal’s reigning box-office champ, animated 3D film “Despicable Me.”

As for “Inception,” the film is most often compared to Warner’s 1999 film “The Matrix,” another highly stylized sci-fi movie that posed the question: Which reality is reality?

“The Matrix” opened to only $27.8 million before securing a domestic haul of $171.5 million, showing the kind impressive multiples that can happen when an exciting sci-fi film starts to generate word-of-mouth.